Unlike most diplomatic memoirs, which deal with weighty matters of politics and foreign relations, Conroy's (Our Man in Belize, etc.) reminiscences are a lark. As U.S. vice consul (and later consul) in Vienna between 1963 and 1966, he seems to have dealt mostly with visa-related matters, judging from these latest sprightly recollections. Apart from a brief meeting with Simon Wiesenthal, who was operating a clearinghouse for information about the fate of European Jewry, most of the book consists of amusing if repetitious stories about eccentric, colorful, odd or desperate visa applicants. They include a mad Yugoslav inventor, a belly dancer whose Egyptian work permit had expired, an opera singer who was being stalked by another singer, an American teenage girl living in a derelict abandoned palace and a Czech gold smuggler posing as a dentist. There are tales of hair-raising escapes from Iron Curtain countries, of lovers reunited. Two of Conroy's immigration cases ended badly, with each woman dying in suspicious circumstances: one was mob-affiliated Virginia Hill Hauser, expatriate Southerner and former lover of ""Bugsy"" Siegel; the other, Austrian-American Ilse Schmidt, fled Baghdad, she told Conroy, after killing her bigamist Iraqi husband in self-defense. A droll observer of the human predicament, Conroy exudes a healthy disrespect for hierarchy, bosses, authority and received wisdom. While this self-indulgent memoir, which closes with his transfer to Washington as science liaison for the Atomic Energy Commission, lacks the sparkle of his Belize book, his comic misadventures nevertheless add up to a witty Thurberesque catalogue of human foibles, pretense, quirks and folly. Photos and drawings. (Aug.)